Pleth Variability Index: A Potential New Marker for Predicting the Mortality of Pulmonary Embolism?

Pulmonary embolism(PE) is a ventilation/perfusion disorder caused by obstruction of the pulmonary artery, usually by a thrombus. The Pleth Variability Index(PVI) is a continuous, noninvasive indicator of dynamic perfusion index(PI) changes in photoplethysmography that occur in at least one respiratory cycle. The aim of this study is to evaluate the prognostic and mortality indicator role of PVI in patients with PE, hypothesizing that PVI could serve as a valuable guide in this disease where perfusion impairment is fundamental.

In the emergency department, data were recorded for patients over 18 years of age diagnosed with pulmonary embolism, demographic data, risk scores and measurements. PVI and PI values were analyzed across different scoring systems, hospitalization statuses, and mortality groups. A survival analysis was conducted to evaluate the impact of PVI and PI on 1-year mortality in patients. The study was assessed with the STROBE checklist.

A total of 49 patients were included in this prospective, single-center study. The PVI value was significantly higher, whereas the PI value was significantly lower in the exitus group compared to the living group (p=0.027, p=0.011). The area under the curve values for PVI, pulmonary embolism severity index (PESI) score, and PI were determined to be 0.714, 0.820, and 0.745, respectively. It was observed that the negative predictive value of PESI was 100%, while the positive predictive value of PVI was the highest at 53.5%. In the. The mean survival time was significantly shorter for patients with PVI >40 and PI <1.9 (p=0.001, p=0.002). An increase in PVI was associated with a 4.04-fold increase in the risk of death (HR: 5.04, 95% CI: 1.50-16.92, p=0.009).

PVI can be considered a noninvasive, rapid, and objective tool for predicting the course and mortality of the disease in PE patients in the emergency department. Our study is the first to evaluate the PVI in PE.